Kubernetes Operators

Description

Copyright Table of Contents Preface Who This Book Is For What You Will Learn Operator Framework and SDK Other Operator Tools Conventions Used in This Book Using Code Examples O’Reilly Online Learning How to Contact Us Acknowledgments Chapter 1. Operators Teach Kubernetes New Tricks How Kubernetes Works Example: Stateless Web Server Stateful Is Hard Operators Are Software SREs How Operators Work Kubernetes CRs How Operators Are Made Example: The etcd Operator The Case of the Missing Member Who Are Operators For? Operator Adoption Let’s Get Going! Chapter 2. Running Operators Setting Up an Operator Lab Cluster Version Requirements Authorization Requirements Standard Tools and Techniques Suggested Cluster Configurations Checking Your Cluster Version Running a Simple Operator A Common Starting Point Fetching the etcd Operator Manifests CRs: Custom API Endpoints Who Am I: Defining an Operator Service Account Deploying the etcd Operator Declaring an etcd Cluster Exercising etcd Scaling the etcd Cluster Failure and Automated Recovery Upgrading etcd Clusters Cleaning Up Summary Chapter 3. Operators at the Kubernetes Interface Standard Scaling: The ReplicaSet Resource Custom Resources CR or ConfigMap? Custom Controllers Operator Scopes Namespace Scope Cluster-Scoped Operators Authorization Service Accounts Roles RoleBindings ClusterRoles and ClusterRoleBindings Summary Chapter 4. The Operator Framework Operator Framework Origins Operator Maturity Model Operator SDK Installing the Operator SDK Tool Operator Lifecycle Manager Operator Metering Summary Chapter 5. Sample Application: Visitors Site Application Overview Installation with Manifests Deploying MySQL Backend Frontend Deploying the Manifests Accessing the Visitors Site Cleaning Up Summary Chapter 6. Adapter Operators Helm Operator Building the Operator Fleshing Out the CRD Reviewing Operator Permissions Running the Helm Operator Ansible Operator Building the Operator Fleshing Out the CRD Reviewing Operator Permissions Running the Ansible Operator Testing an Operator Summary Resources Chapter 7. Operators in Go with the Operator SDK Initializing the Operator Operator Scope Custom Resource Definitions Defining the Go Types The CRD Manifest Operator Permissions Controller The Reconcile Function Operator Writing Tips Retrieving the Resource Child Resource Creation Child Resource Deletion Child Resource Naming Idempotency Operator Impact Running an Operator Locally Visitors Site Example Summary Resources Chapter 8. Operator Lifecycle Manager OLM Custom Resources ClusterServiceVersion CatalogSource Subscription InstallPlan OperatorGroup Installing OLM Using OLM Exploring the Operator Deleting the Operator OLM Bundle Metadata Files Custom Resource Definitions Cluster Service Version File Package Manifest File Writing a Cluster Service Version File Generating a File Skeleton Metadata Owned CRDs Required CRDs Install Modes Versioning and Updating Writing a Package Manifest File Running Locally Prerequisites Building the OLM Bundle Installing the Operator Through OLM Testing the Running Operator Visitors Site Operator Example Summary Resources Chapter 9. Operator Philosophy SRE for Every Application Toil Not, Neither Spin Automatable: Work Your Computer Would Like Running in Place: Work of No Enduring Value Growing Pains: Work That Expands with the System Operators: Kubernetes Application Reliability Engineering Managing Application State Golden Signals Sent to Software Seven Habits of Highly Successful Operators Summary Chapter 10. Getting Involved Feature Requests and Reporting Bugs Contributing Sharing Operators Summary Appendix A. Running an Operator as a Deployment Inside a Cluster Appendix B. Custom Resource Validation Appendix C. Role-Based Access Control (RBAC) Fine-Tuning the Role Index About the Authors Colophon